Cream butter and sugar until light and fluffy.
Beat in egg, vanilla, and milk.
Sift cocoa and flour.
Mix into butter mixture until thoroughly blended.
Chill dough until firm enough to handle (about 30 minutes).
Using 2 tablespoons dough, roll a rope about 12 inches long between your hands.
Shape into pretzel as follows: Make loop about 1 1/2 inches in diameter by crossing ends, leaving 1-inch tails.
Flip loop down over crossed ends.
Press firmly into place.
Place on greased baking sheets.
Bake at 350Â°F about 10 minutes.
When cool, spread with Cocoa Frosting.